Without doubt the Sabertooth Mark 2 is the superior choice. It's a revised version of the Mark 1 with updated software included, a more recent BIOS and, perhaps most importantly, an SATA Express connector allowing faster Hard Drive access speeds.
There may be a slight cost difference but the future proofing and overall niftyness of SATA Express is certainly worth it in my opinion.
Be sure to make use of this connector for a Solid State Drive if you get the chance, to maximise the near-instant access rates of such a device.